DE3710731A1 - POLYURETHANE FOAMING FUEL WITH SOUND INSULATING AND ENDOWING PROPERTIES - Google Patents

Description

The present invention relates to a flexible polyurethane foam, which is especially good for sound insulation suitable. It is characterized in that in addition to an airborne sound absorption and soundproofing in mass-spring systems also the Entdröhnungswirkung used for sound insulation be able to do so by virtue of his Surface finish good contact with a too drone Sheet metal possible.

It is the different polyurethane flexible foams known for sound insulation, but they are suitable not, as the foam according to the invention, for Entdröhnung. Thus, DE-AS 19 23 161 and DE-OS 28 35 329 mineral-filled foams due to Their high density of 0.5 to 1.25 kg / dm³ good sound insulation enable. A Entdröhnung of sheets is with However, these materials are not possible because the loss factor these foams is too low.

Although DE-PS 27 56 622 is on the production of foams turned off with high loss factors, but that is described method, namely the impregnation of open-pored polyurethane or PVC foams with viscoelastic raw materials, z. B. inorganic fillers containing polyolefins or organic resins or waxes, with considerable Effort connected.

DE-PS 33 13 624 also relates to the production of a Flexible polyurethane foam with high loss factor. But leave the viscoelastic properties are not easy for the Entdröhnung of sheets, such. B. Body floor groups and end walls in motor vehicles use because of Entdröhnung a coupling between the sound to be droned and the viscoelastic material must be present. This is  not possible without aids in the known foams. For this reason, today compact materials for Enthröhnung melted on vehicle floor groups. This is associated with considerable effort. Because the reflow processes usually done before or during the painting of the bodies, problems with paint pollution occur. The Melting in separate ovens requires a lot of energy connected, so that there is considerable interest, to make the Entdröhnung without separate melting processes.

It was also the attempt undertaken (DE-OS 35 10 932) the viscoelastic properties of a foam by adhesive Coatings for coupling between sheet metal and foam but the process is at an extra expense connected.

The invention is therefore based on the object, a polyurethane foam to develop, which avoids these disadvantages and besides an improvement in airborne sound absorption and Airborne sound insulation in so-called mass-spring systems in addition the Entdröhnung of sheets allows.

This object is achieved in that a flexible polyurethane foam was developed due to its composition an inherently adhesive surface and additionally one Loss factor of over 0.4 has.

It has been found that the adhesive properties, the conditions for the transmission of damping properties, are dependent on the setting of the index (NCO index) of a polyurethane mixture. Surprisingly and unforeseeable for the skilled worker, it was found that an optimum of the adhesive properties can only be achieved if the characteristic values of 80 to 50 are adhered to (see FIG. 2). Furthermore, it was not foreseeable that even in this area of the setting of the characteristic also good damping properties of the foam are adjustable (see Fig. 1).

Polyurethane foams with this combination of properties are new and not yet known; they open the in The task described new opportunities Concepts of soundproofing and are therefore of considerable importance Interest.

The foams of the invention are also suitable for foaming of heavy foil and carpets, so that in addition to the sound-deadening effect also airborne sound insulation properties can be used. Due to the low modulus of elasticity are suitable They are also suitable for use as a spring in mass spring sy Stemen.

The present invention accordingly relates to a flexible polyurethane foam for soundproofing purposes having an adhesive surface, which is obtained by reacting a polyisocyanate or a Polyisocyanatpräpolymers with an excess of polyols or mixtures thereof using an NCO index of 80, bes. ≦ 70 and having a density of 80 kg / m³- 250 kg / m³, has an E- modulus of less than 300 000 N / m² and a loss factor of at least 0.4.

As polyols come z. B. in question: polyether polyols, in particular based on ethylene oxide and / or propylene oxide. Suitable polyisocyanates are in addition to diphenylmethane-4,4- diisocyanate with NCO content 31% based on MDI and such with different NCO content.

The production of the foam according to the invention takes place preferably by means of the RIM process (Reaction Injection Molding). In this way, foam parts can also in combination with other materials, such. B. tissue inserts,  Fleece inserts, foam backing of heavy layers or carpets or textiles. The form life time can be accelerated to less than 3 minutes adjust what a cost-effective production of moldings allows.

The foam of the invention is according to the prior Technology corresponding rules for cold formed foams (eg G. Woods "Flexible Polyurethane Foams", Chemistry and Technology, 1982, 206 ff).

However, the decisive factor here is that compliance with the Key figure in the above range is respected.

The invention will be explained in more detail with reference to the following Examples and the drawings explained in more detail. Show it

Fig. 1 and 2 properties of the foams obtained,

FIGS. 3 and 4 respectively in different shaping an applied to a system constituted by a profiled sheet metal wall part sound insulating adhesive insulation system as a wall covering, that uses the flexible polyurethane foam according to the invention,

Fig. 5, 6 each in a different shape according to FIGS. 3 and 4, a sound insulation system as wall covering with applied via a decoupler carpet.

example

According to the following guideline were different foams manufactured:  

Comp. A

48.0 G.-T. Polyether polyol based on propylene oxide and ethylene oxide (42 mg KOH / g, MW 4000) 18.0 G.-T. Castor (160 + 10 KOH / g, Aeg. 340 + 20) 26.0 G.-T. Polypropylene glycol (250 mg KOH / g, MW 450) 6.0 G.-T. Polyether polyol based on polyethylene oxide and propylene oxide (28 mg KOH / g, MW 4900) (cell regulator) 1.0 G.-T. least. Water (blowing agent)  1.0 G.-T. Auxiliaries (such as dimethylethanolamine, dibutyltin dilaurate) 100.0 G.-T.

Comp. B: diphenylmethane-4,4-diisocyanate (NCO content: 31%)

Then, the component A and the component B were in the proportions given in the table below Mixing head fed to a RIM system and in a mold too Foamed an open-cell foam part. The demoulding takes place after 3 minutes.

The properties of the obtained foams are shown in the table and in Figs. 1 and 2. The density of the foam was about 120 g / dm³.

table

Technical-physical data

The provisions of the adhesive properties were as follows carried out:

experimental setup

• 1. Universal testing machine of the company Frank, Weinheim, type 21 004,
  Top plate 50 × 50 mm
  Plate below 200 × 200 mm.
• 2. Sample size 50 × 50 mm.
• 3rd speed 25 mm / min.

Experimental Procedure

The samples are 4 mm (load cell 500 N) and the power suits the machine is zeroed.

Then the plate was 25 mm / min. driven up and the power at Separation noted. After each sample were the plates with detergent 60/95 cleaned.

The use of flexible polyurethane foams according to the invention is explained in more detail with reference to FIGS. 3 and 4 or 5 and 6.

The sheet forming the wall part 1 as a sheet metal has profilings, which are formed as a molding wall cladding, namely an insulation system 3 with overlying carpet 8 follows, always about the same thickness of the wall cladding is maintained. The wall cladding is adhesively applied to the wall part 1 , without having to use an adhesive, namely by means of the adhesive effect at the point 2 facing consisting of inventive flexible polyurethane foams insulation system. 3

The wall cladding thus consists of the insulation system 3 , which in turn has the so-called spring 4 , 5, the flexible polyurethane foam and a heavy layer forming mass 6 of a filled plastic. Locally different Schalldämmvermögen is achieved by a partial application of the spring 4 , 5 . Optionally, a full-surface uniform Schalldämmvermögen can be achieved by a corresponding full-surface application of the spring 4 , 5 .

The adhesion forces of the spring 4 , 5 itself can be changed virtually continuously in the production of the insulation system 3 , namely by a corresponding control of the mixing ratio. In this case, only a single simple operation is required at substantially constant thickness and locally different Schalldämmvermögen, wherein optionally stiffening covers are also applied. According to FIGS. 4 and 5, a decoupler 7 made of a flexible, predominantly open-pore material is now provided in the wall cladding between the heavy layer 6 and the carpet 8 arranged thereon, preferably a foam, or a nonwoven or felt acoustically acting in the same way. This decoupler 7 is applied as a thin layer with a thickness in the range of about 5 mm. The decoupler 7 causes the otherwise observable reduction in flexural softness when applying a carpet to the insulation system is avoided, moreover, surprisingly, not only maintained the acoustic effect, but is usually even improved. In addition, such an arrangement is easily processed in a conventional manner.

Claims (10)

1. Flexible polyurethane foams with sound-insulating and enthroning properties, obtainable by reacting a polyisocyanate or polyisocyanate prepolymer with polyols present in excess or mixtures thereof while maintaining an NCO index of 80, especially 70 in order to produce an adhesive surface and further characterized by a density of 80 to 250 kg / m³, an E modulus of <300 000 N / m² and a loss factor of at least 0.4. 2. Process for producing a flexible polyurethane foam according to claim 1, characterized, that is a polyisocyanate or Polyisocyanatpräpolymer containing component with the polyols or mixtures thereof in excess containing component while maintaining from an NCO index of 80, especially by feeding into the mixing head of a RIM Investment. 3. Use of the flexible polyurethane foams with adhesive surface as an insulation system ( 3 ) for the entdröhnende sound insulation especially in motor vehicles, especially with downstream layers ( 6 , 8 ), such as a heavy layer ( 6 ) and a carpet ( 8 ). 4. Use according to claim 3, characterized in that on the insulation system ( 3 ) applied carpet ( 8 ) between the heavy layer ( 6 ) of the insulation system ( 3 ) and the carpet ( 8 ) a decoupler ( 7 ) made of soft elastic predominantly porous material is arranged. 5. Use according to claim 4, characterized in that the decoupler ( 7 ) consists of foam. 6. Use according to claim 4, characterized, that the decoupler of acoustically effective nonwoven or Felt exists. 7. Use according to one of claims 4 to 6, characterized in that the decoupler ( 7 ) is formed thin in the range of about 5 mm. 8. Use according to one of claims 4 to 7, characterized in that the adhesion forces bound by the downstream layers ( 4, 5, 6 ) have acoustically damping properties. 9. Use according to one of claims 3 to 8, characterized in that the adhesive coating ( 2 ) is wholly or partially executed. 10. Adhesive insulation system according to one of claims 3 to 5, characterized in that the adhesive coating ( 2 ) is provided with rigid covers made of cardboard, kraft paper, sprayable, curable plastics or the like.